If you haven't done so already, please PM me or mail us and we'll investigate further. If you can provide information on the browser you're using including version, OS being used, etc it will all help. If there's anything that you'd like to order but are unable to do so because of the issue, please let us know and we'll assist in placing the order for you, in the meantime.
I noticed my cart was cleared after I left items in for a long time - I thought it was just a feature that it is cleared automatically if you leave items in there...